September 29, 2016

The heater that made ice

PEOPLE HAVE TRIED to persuade me that if you have a heater on your boat you can extend your sailing season by six weeks or so at each end. I have never been swayed by that argument. Having spent a great deal of my life in the sub-tropics, I have no love of sailing in the cold. Or the cold-and-rain, as often happens around here.

There was a heater of sorts on a boat I once had, a little Cape Dory 25D. My wife and I found her on an island in north Puget Sound, and sailed her home one bitter-cold day in February, when there was ice on deck. We had an overnight stop in a marina in Anacortes, where we ran into an old sailing friend. He offered us an electric heater because he said a cold night was forecast, but we scoffed and turned him away. “We have a nice Force 10 heater installed,” we said.

After a meal ashore, we came back to the boat and lit the heater. It had started life as a kerosene model, but the previous owner had converted it to gas. A small can of propane screwed onto the bottom.

We soon noticed something strange. It didn’t seem to be producing a lot of heat, and what heat it did produce rose to the top of the cabin and stayed there. What was even stranger was the fact that the can of propane was collecting a coat of ice. If we stood up in the cabin, the air was luke-warm from the belly-button up, and freezing cold from the belly-button down. As the layer of ice on the can grew thicker, we shut the heater off, fearing that it was actually producing more cold than heat on average. Our bunks were below belly-button level, so we spent a very cold night aboard, having brought only light-weight sleeping bags with us, and regretted having turned away the offer of the electric heater.

One of the first jobs I did on that boat was to convert the Force 10 back to kerosene heat.

It was a fairly easy job once I’d bought the right tools for flaring the copper tubing and so on. The new burner put out a lot more heat and never tried to make ice, but the hot air still hung around above belly-button level until we bought a 12-volt fan and mounted it where a reading lamp used to be. That stirred the air up nicely, distributing warmth all over the cabin from head to toe.

But we rarely used that heater because the fan used electricity, and I was scared we might flatten the battery overnight and not be able to start the diesel engine on a cold morning.

I have learned over the years that very little is simple on a boat, and the less you have to go wrong the better off you are. So I’m not overly enthusiastic about heaters on boats in our part of the world. That of course provides me with a very handy excuse for not sailing when the weather gets cold, which is fine with me.   

Today’s Thought

What is true, simple and sincere is most congenial to man’s nature.

— Cicero, De Officiis


“Who gave you that black eye?”

“My wife.”

“I thought she was out of town.”

“So did I.”


Alden Smith said...

Heaters in small spaces is problematic and sometimes lethal. A naked flame burns oxygen and there are cases where in tightly sealed tents, cabins and boats people have been asphyxiated.

Project Infinito said...

Great post as always. If you sail an otherwise tropics-prepared boat to, say, Patagonia, should you get a cabin heater or is it more of a luxury?
John, something is happening to your blog in which one can no longer see the most recent post in the home page. When I access the weblink "" I get an error message that says "Sorry, the page you were looking for in this blog does not exist." I can only see your most recent post by clicking on it on the right side of the page. It could be my computer but just wanted to let you know in case other users may be experiencing the same thing.

John Vigor said...

Project Infinito, I have no problem with so I wonder if it's your computer. You might also want to try my website and click on "Blog" at the top of the page.
As for Patagonia and points south, I would think a cabin heater is an essential, not a luxury. The cold down there is greatly intensified by humidity building up in the cabin, and a heater is really the only way to dry things out in a hurry.
John V.

Project Infinito said...

Thanks John! The blog is back at full function for me now.
Indeed, I'll look for the best heater in case I start heading down there in the next years.

Rob Morton said...

Hi John,

I got a chuckle out of your heater dilemma. I made a heater out of an inverted stainless steel saucepan and put a vent to the outside. It works pretty well especially with a small fan running.